Source : Webster's Revised Unabridged Dictionary (1913)

Osculatrix \Os`cu*la"trix\, n.; pl. {Osculatrixes}. [NL.]
   (Geom.)
   A curve whose contact with a given curve, at a given point,
   is of a higher order (or involves the equality of a greater
   number of successive differential coefficients of the
   ordinates of the curves taken at that point) than that of any
   other curve of the same kind.